Method for making producer gas



July 14, 1931. y c. w. ANDREWS 1,814,580

METHOD FOR MAKING PRODUCER GAS Filed oct. 31, 1925 Patented July 14,1931 UNITED STATES PATENT OFFICE CHARLES w. ANDREWS, or DULU'III,MINNEsorA, AssIGNOB, BY branca" ANnnasNn AssIeNMEN'rs, fro n. A.BnAssEafr a COMPANY, or CHICAGO, ILLINoIs, A conronA- TION 0F ILLINOISMETHOD FOB MAKING PRODUCER GAS Application led October 31, 1925. SerialNo. 65,940.

This invention relates to a new `and improved method for making producergas and more particularly, to such a method in which thermal eiciency isincreased by operation under'the counter-current 'principle of heattransfer.

It is well known in the art that the amount of steam used in gasproducers is largely governed by the character of the ash. Should itclinker easily, more steam is required to prevent clinkers as up to thepresent time there is n0 mechanical ash removing device vwhich willadequately handle large pieces of hard clinker.` Although the slaggingtype of gas producer llas been developed to solve this problem and alsomakes possible a deep fuel bed, nevertheless no commercial installationsare known to be in use in this country owing to trouble in making liquidslag and removing it.

It is recognized that carbon monoxide is a better gas than hydrogen formany heating operations on account of its greater specific gravity andalso on account of the increased radiation from the burning gas. .It isalso recognized that the undecomposed steam passing through the produceris detrimental V as it not only requires heat to makeit, but

it also carries out of the fire bed its own sensible heat. This isespecially objectionable in high temperature operation as the flametemperature is materially lowered. The amount of blast furnace gas orother carbon dioxide containing gases it fis possible to use in place ofsteam, depends upon the lire temperature which must be suiciently high,not only to effect the desired decomposition of carbon dioxide, andalso, the decomposition of the small quantity of water vapor which is'usually found with the ases, but also to supply the amount of sensibleheat the gases carry out of the vfire bed of a prbducer. This is aconsiderable item as gas producers ordinarily run at a top temperaturearound 1300 to 14009 F.4

It is evident that if the counter-current principle of heat transfercould be .used a material saving could be obtained` How.

ever, the result of such a procedure would be the formation of largeclinker masses,

which up to this time has made such a 4method of operationimpracticable.

The applicant has recognized. the above and in co-pending applications"has sought to better thesel results by various means. The application ofthe applicant, Serial No. 1,157, filed January 8, 1925, issued A ril 16,1929 as Patent N 0. 1,709,107, disc osea a method of breaking u suchclinkers and the joint application of apman and the applicant, `SerialNo. 737 ,238 filed September 12, 1924, issued April 16, 1929, as PatentNo. 1,709,834, shows the necessary mechanical means to accomplish thepurpose. Inasmuch as these inventions have been perfected, it is nowpossible to operate a gas producer for thermal efficiency without beinghandicapped by the formation of the large clinkers. Relatively deep firebeds and also much higher temperatures can be used, both resulting inalargely increased roduction per unit of capacity and also ma 'ng abettergas, as practically all of the steam used will be decomposed andthe ercentage of CO2 reduced to a minimum. t is also now possible tooperate such a producer so as to take advantage of the counter-currentkprinciple, referred to above. Air and steam or blast furnace and othergases may be admitted from either top or bottom, either together oralternately, whatever way may be most desirable. Blast furnace or othergases it provides `means for producing the required steam, or acts as astandby source of steam supply should blast furnace or other gases benormally used, as the checkerbrick in the regenerators can be soconstructed as to be readilyused as a flash boiler.

It is an object of the present invention to provide new and 4improvedmeans for the leaving the apparatus is reduced` to a minimum and whichmay be carried out in various manners by the joint or separate use ofair, steam vand metallurgical gases containing a considerable portion ofcarbon dioxide. l y

Other and further objects will appear as the description proceeds.

I have illustrated in the accompanying drawings a,v preferred form ofapparatus' ada ted for carrying out my improved method, the apparatusbeing in itself no part of the present invention.

In the drawings,

lFigure 1 is a vertical section of the apparatus and Figure 2 is ahorizontal section taken on line 2 2 of Figure 1.

The apparatus comprises the gas producer 11 having the charging bell 12and the fixed grate 13. The bar or agitating beam 14 extends across thegrate and has its ends secured to the ring 15 whichA rotates upon theballs 16. The lower portion of the rlng 1s provided with the gear 17which 1s driven by means of pinion 18. Power is supplied to the'pinion18 in any desired manner. The

bottom of the producer is entirely enclosed` by the housing 19. Thelcircular ash tray 20 is carried b the ring 15 and ashes are scooped fromthe tray bymeans of the adjustable scoop 21. Ashes are moved through thedoor 22. Ashes falling through the grate 13 may be removed through thedoor 23. The bottom housing 19 is connected to the passage 24 controlledby valve 25 and. the passage 26 controlled by valve 27 leads from theassage 24.

T is type of apparatus is shown more yin detail in my co-pendingapplication, Serial Y N o. 1,157 filed J anuaryk 8, 1925 now issued asPatent 1,709,107 of April 16, 1929. The reenerator 28 which 1s providedwith the eating flues 29 has its upper end connected by passage 30 withthe upper end of the gas producer 11. The passage 31 controlled by valve32 leads into the lower end of the regenerator 28. The passa e 33controlled by valve 34 leads upwardly rom the passage 31.

In carrying out my method by the use of this a paratus, the air,` airand steam, or blast Furnace .or other gases such as spent or burntor-partially burnt gases from other furnaces or apparatus, andcontaining carbon dioxide and which are to be used are 1,'s14,5so t"introduced through the passage 24, the valve 25 being opened. These passupwardly through the ash and clinker inthe bottom of the producer, thenthrough the lire zone and upwardly through the raw fuel in the upperportion of the producer in which a thick fuel bed may be' carried. Theoxygen in the gases unites with the carbon of the fuel to form carbonmonoxide and this gas forms the basis of the gas desired. The heatedgases, after giving up some of their heat to the fuel in the upperportion of the producer then pass through passage 30 to the regenerator28 where they give up additional heat and are led off through passage3l, valve 34 being closed and valve 32 being opened, to the desiredpoint of use or to gas holding apparatus, not shown. The gas run may bethen reversed and the incoming gas or gases brought in through passa e31, and passed through the regenerator w ere they pick up heat, thenpassed down through the fuel and out through the clinker and ash wherethey give up much of their heat before being led o through the passage24 to the point of use or to a gas holder.

It will be understood that the gasesvused and introduced into theproducer may be widely varied. Steam and air may be introduced`alternately or together. It should be noted, however, that thisalternate introduction of steam and air will not be for the purpose ofproducing water gas according to the water gascycle of operation. Thegas to be made is producer gas containing nitrogen and with carbonmonoxide as its major combustible component. The air may be introducedunder low pressure as in producer practice and when the heat of the fireis raised to as high a point as is desired for the production of carbonmonoxide, irrespective of the formation of large clinkers,

the supply of air will be shut off and steam introduced to cool thefire, largely by its decomposition, to such a degree as may be desiredfor eflicient operation. The steam may be introduced together ifdesired, in which case, they will be proportioned so as to maintain thedesired fire temperatures for gas production withoutvrelation to clinkerformation.

It will be understood that the main purpose for the introduction ofsteam in usual producer practice is not the production of blue watergasto mingle with the carbon monoxide formed by the im rfect combustioncaused by the air intro uced, but is the maintenance of proper workingtemperatures vand the utilization of the excess heat of the-combustion.A continuous air blast alone would produce a gas of low latent heatcontentleaving the producer at a high temperature with consequent lossof sensible heat and would ,further raise the temperature in theproducer so high as to clog it air. and` with molten slag. By theintroduction of steam in proper proportions, the excess heat of theexothermic reaction of combustion is utilized in the endothermicreaction of dissociating the steam. The products of the latter reactionare combustible and thus much of the heat is utilized in making usefulgas. Due to continuous operation in one direction, however, in ordinaryproducers much sensible heat is lost as the gas leaves the producer at arelatively high temperature.

Metallurgical gases such as blast furnace or -other gases which containmuch carbon dioxide together with some carbon dioxide land water vapor,may be substituted for steam in my improved method of operation. Thesegases reduce the temperature in the producer and utilize the excess heatof combustion by the endothermic reaction of breaking downthe CO2 tolC() as well as the reaction of breaking down the water of any watervapor content. Such gases thus function in substantially the same way assteam insofar as the process broadly is concerned.

Where blast furnace orlother metallurgical gases are used, which gasescontain a large proportion of carbon dioxide, these gases may bealternately introduced from above and below as has been described. Thecarbon dioxide of the gases will react upon the carbon of the fuel andwill be largely broken down to carbon monoxide, thus very greatlyraising the heatvalue ofthe gas.

By the use of apparatusof the general type shown and described, mymethod may be advantageously carried out. A minimum of heat is carriedaway -from the apparatus, since by the application of thecounter-current principle much ofthe heat is retained. In the downrun,this heat is retained in the clinker and ash below the fire zone and ispickedV u by the incoming gases u on the uprun. llpon the uprun, in theorm of construction shown, some of the'heat is retained by the fuelabove the fire zone in the producer and additional heat is retained inthe re enerators shown. f

Obviously, the apparatus `is capable of modification, such for example,as sup lying an additional regenerator associate with passage 24 so thatregeneration of the incoming air and gas may be had 1n both up and downruns. On the other hand, the regenerator shown may be dispensed with andby usin deep fuel beds, the ash and clinker below t e fire zone and thefuel above the fire zone may be the sole regenerating means. Therevolving bar of the type shownserves .to drop the clinkers off of itsvertical edge and to break them u into small masses -which are readilydisc arged and removed. The method of operation which produces largeclinker masses is, therefore, 'not objectionable when usingthisapparatus since without diiiculty in the normal tinuously breakinthese masses are broken up and removed operation of the apparatus.

When using blast furnace gases in the producer, these gases will be usedas they come from the blast furnaces without being washed and theircontent of iron and other materials will be takenup bythe fuel and ashin the producer as the gas is passed through. The iron. will be presentin the clinker coming from the producer and this clinker maybe chargedback into the blast furnace and the iron recovered in this manner. Nosintering will be necessary. This method, therefore, has the advantageof recovering the iron content of the blast gases directly in a usableform and avoids the necessity for washing the gases. The ases are alsoenriched by largely breaking own their carbon dioxide content to carbonmonoxide.

While one form of apparatus particularly ada ted for carrying out myprocess has been s own in the accompanying drawings, it is to beunderstood that it may be carried out by other apparatus and'Icontemplate such changes and modifications as come within the spirit andscope of the appended claims.

1. The method of making producer gas, which comprises admitting mixturesof air and gases containing a substantial quantity of carbon` dioxidegases, said gases being capable of forming more combustible gasesthrough endothermic reactions in a highly heated deep fuel bed, saidadmissions being alternately from the top and bottom of a gas producer,the periods of alternation being so timed as tocausethe sensible heat ofthe out-going gases to be largely transferred to the incoming gases, andcontinuously breakin up and removing mechanically the as es and clinkerswhich form.

2. The method of making producer gas, which comprises the successiveadmission of air and of combustible gases containing substantialquantities of carbon dioxide, said combustible gas being capable offorming more highly combustible gas through endothermic reactions in ahighly heated deep fuel bed said successive admissions of air and gasbeing alternately from the top and bottom of a producer, the-periods ofalternation being such asA to vcause the sensible heat of the out-goinggases to be largely transferred to the in-comin gases, and conup anremoving mechanically the as es and clinkers which form.

y 3. The method of making producer gas which comprises thesuccessiveadmission o lmixed aix` and combustible gases containing substantialquantities 'of carbon dioxide, 130

said combustible gas being capable of forming more highlyvcombustiblegas through endothermic reactions in a highly heated deep fuel .bed',such said successive admissions of mixed air and gas being alternatelyfrom the top and bottom of a gas producer passing the outgoing generatedproducer gas into a regenerator'inheat exchange with the incoming airand gas whereby the sensible heat of. the producer gas is largelytransferred to the inco mixed air and gas, and continuously brealn'ng upand removing mechanically by an agitating beam,'the ashes and clinkerswhich form.

Signed at Chicago, Illinois, this 28th day of October, 1925.

CHARLES W. ANDREWS.

